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Anonymous Poster

power factor question

11/30/2008 3:08 PM

Hi all

Anybody got any ideas on the following. I'm snookered without the voltage

if a single phase motor operates at a pf of 0.75 lagging and takes 25A from the supply without any pf improvement. if the supply freq. is 50 Hz calculate the capacitance reqd to reduce the supply current to 20A with a lagging pf. Determine the new supply current.
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Sapper
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#1

Re: power factor question

11/30/2008 5:43 PM

Based on your frequency being 50Hz, I would assume 240V since most countries running 50Hz are 240V.

Regards,
Sapper.

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user-deleted-13
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#2

Re: power factor question

12/01/2008 12:17 AM

Sure sounds like a homework or take-home quiz question to me. We'd be glad to help, but this smells fishy.

Tell you what. You tell us the motor manufacturer, motor model number, ratings, and type of motor, and we'll return the favor.

And if this is a homework question, try to work it out and, if you can't, show us where you're having difficulty (show us your work) and we'll help you with it.

We don't do students' homework for them on this forum. Students do their own homework. But we're happy to tutor, if that's what you need. Your part in this is being honest with us.

Deal?
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Anonymous Poster
#3

Re: power factor question

12/01/2008 10:16 AM

Thanks sapper that makes sense
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sb
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Join Date: Mar 2007
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#4

Re: power factor question

12/01/2008 10:03 PM

Do you need to know the voltage?

Pl use simple phasor equation (The question looks like a homework so no more hints)

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